Polyphase sequence indicator



April l1, 1950 l.. l.. slMKlNs PoLYPHAsE SEQUENCE INDICATOR Filed May1o, 1946' -INVEN TOR.

l Irrrrrzvbrr v PHAE 5E Patented Apr. 11, 1950 POLYPHASE SEQUENCEINDICATOR Leon L. Simkins, Kalamazoo, Mich., assignor to The WiggintonCompany, Kalamazoo, Mich.

Application May '10, 1946, 'Serial No. 668,834

7 Claims- The main objects lof this invention are:

First, to provide an electrical phase sequence indicating instrumentusable though a wide 'range of voltages.

Second, to provide an electrical phase sequence indicating instrument ofthe mechanical type which does not require continuously rotating parts.

Third, to provide an electrical phase sequence indicating yinstrumentwith linkage for maintaining the instrument in neutral position when notin use.

Other objects and advantages of this invention will be -apparent yfrom aconsideration of the following description and the accompanying drawingsof ywhich there is one sheet and in which:

Fig. 1 represents a perspective view of a commercial embodiment of theinvention.

Fig. 2 represents a plan view `of the mechanism of the instrument withthe case removed.

Fig. 3 represents a vertical cross-sectional view taken along the planeindicated by the line 3--3 in Fig. 1 yand looking in the direction ofthe arrows.

Fig. 4 represents a schematic wiring diagram of the instrument.

Fig. 15 represents a horizontal vcross-sectional view taken along a planindicated by the line 5-5 in Fig. 3 and looking in the direction of thearrows.

It has previouslybeen proposed to make instruments for indicating thephase rotation of 'polyphase electrical circuits employing lampindicators or mechanical rotating mechanisms which were in fact smallelectric motors. 'This invention provides a simplified instrument of themechanical indicating type.

'Indicated by the reference character Il) is the testinstrument whichisprovided with vtest'leads I2, I4, and I6, each of which has a springclamp I8 connected to the end thereof. 'The connections between theleads and the spring clamps .are covered with insulating sleeves 2twhich it is preferred to make of different colored rubber to correspondto the connections of the leads vwithin the instrument as indicated onthe face of the instrument. The leads are enclosed by a iiexible conduit22 through a portion of their length and enter the case l0 through atiexible grommet '24.

With reference to Figs. 3 and 5, it vwill be noted that the case IUconsists of a box 26 one side of which defines an aperture throughvwhich the -grommet 24extends and a cover 28. The cover is arranged tobe secured tothe box vby means 2 ofthe four lscrews v3l! passed throughthe corners of the cover.

Secured to the inner side of the cover 28 by means of the screws 32 andspaced therefrom by means of the sleeves 34 is a plate 36 with abackwardly bent flange 38. 'The plate 36 vserves `as :asupport for theU-shaped spring clip 4B which `is secured thereto by means of the bolt42. The bolt 42 extends through the'plate and also serves to securelboth leaves of a spring switch 44 to the forward side of the plate.

Removably vretained in the spring clip 40 are the twocylindricalcondensers llt which are electrically connected 2in lparallelat one end to the switch 44 by means of the conductor 48, and vat theother end by means of the conductor 50 to ya contact common to each oftwo coils.

Secured to the upper side of the flange 38 and having va -do-wnwardlybent portion is the coil support member 52. The support member 52extends downwardly to adjacent the lower edge of the box and is therebent into a U-shaped portion 54. The pin 56 passing' through both legsofthe U-shaped portion 54 secures the lower end of the coil supportmember to the lower vend ofthe cover 28. The support 52 is furtherprovided as indicated in Fig. 2 with laterally extended ear sections 58through which the screws 60 are passed to support the lower ends of apair of coils l2. The upper ends of the coils 62 yare ysecured in placebymeans of pins projecting into the under side ofthe flange 38 on theupperrsupport 36.

A U-shaped indicator 64 is pivotally mounted on the pin 56 and isprovided with a pointer section B6, laterally extending arms 68 and anupwardly extending arm 'l0 in the cen-ter thereof. The arms 58 areconnected by means of the pins 'H to the 'lower ends of armature members12 positioned vertically within-the coils v(i2. `A vertically extendingcoil spring 1li is yconnected'between theupright arm 'iii and the flange'38 of the lupper support member. The indicator may thus rotate aboutthe .pin 5B in response tomov'ement of either of the armatures l2 butwill lbe returned to a neutral position upon de-energization of thecoils by action of the coil :spring "It on the arm.

The cover 28 is piercedby two openings, 16 and 18, which may be providedwith window closures 80. Aplate '3| on which operating instruction-s andvoltage capacity may bo printed as shown in Fig. l operates to hold thewindows inplace. The cover is also provided with a test button .82 whichis larranged to close the contacts of the 3 switch 44. It will be notedthat the pointer B6 extends upwardly within the instrument to where itmay be viewed through the windows 80 when the instrument is inoperation.

The electrical connections within the instrument are most clearlyindicated in Fig. 4 which shows that one of the leads, such as I2, isconnected to one end of one of the coils 82 while another of the leadsI6 is connected to the end of the other coil 62. The opposite ends ofthe coils 62 are joined together and connected to one side of thecondensers 46 by the conductor 5I) as was explained before.

'I'he remaining lead I4 is connected to the free terminal of the switch44 so that it may be connected through the switch to the other side ofthe condenser. The armatures 'I2 are slidably positioned within thecoils 62 and are arranged to be attracted or pulled upwardly by thepassage of current through the coils.

From theabove description it should be apparent to anyone skilled in theart that if the leads I2, I4, and I6 are connected to a threephaseelectrical system no indication will be shown by the pointer B6 untilthe button BIJl is pressed to close the switch 44. Until that takesplace current will flow equally through both the coils 62 and pressureon the arms 68 by the armatures 'I2 will be balanced. However, onclosing the switch 44 current will ow through the condenser 42 whichwill have a leading characteristic with respect to the currents flowingthrough the conductors I2 and IB. This will cause an unbalance of thecurrent through the coils 62 and one 0f the armatures I2 will beattracted morev strongly than the other. This will rotate the indicator64 against the tension of the spring 14 and cause the pointer 66 toappear through one of the windows 'I6 or 18. If the leads I2, I4 and I6are connected to the circuit being tested corresponding to the phasesequence indications printed on the plate 8|, the phase rotation of thecurrent in the three conductors will be accurately indicated by thepointer 66. The instructions on the plate 8| are arranged to agree withthe internal connections in the instrument. Thus when the red lead I2 isconnected to the top wire of three horizontal wires or the left wire ofthree vertical wires being tested and the black lead is connected to thebottom or right wire of the three wires as the notations over thewindows 'I6 and 'I8 direct, the left coil 62 in Fig. 4 will be energizedfrom the red lead and the right coil will be energized from the blacklead. The condenser will be energized from the center wire and the whitelead when the switch 44 is closed. Since the summation of all currentspassing through the common point of the condenser and coil circuits iszero in a substantially balanced circuit, the leading character of thecurrent in the condenser circuit and white lead I4 causes the unbalancebetween the two coil circuits which results in actuation of the pointer.A complete description and vectorial diagrams showing the relationshipof the currents in a Y connected phase indicator is set out in thepatent to A. R.

Hand No. 2,027,864, issued January 14, 1936. In

all cases, the conductor to which the red lead is attached is consideredas the iirst conductor and the conductor to which the black lead isattached is considered as the third conductor. Then when the pointer 66appears behind the window I6 the instrument indicates that the phaserotation in the three conductors being tested is 1, 2, 3 and when thepointer appears behind the right window 'I8 the phase rotation of thecircuit is 3, 2, 1 as shown by the indicia underneath the windows.

The meter will operate at any voltage within the capacity of the wiringsince its operation depends on the unbalance of current in the two coilsand is not limited to critical voltage such as is the case when lampsare used. The indication is positive and there is no need to judgebetween the brightness of two lamps.

My invention has been illustrated and described in a highly practicalembodiment thereof. I have not attempted to illustrate or describefurther adaptations of the invention, as it is believed this disclosurewill enable those skilled in the art to embody or adapt the invention asmay be desired.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. An electrical phase sequence indicating instrument comprising a pairof coils and a condenser continuously electrically connected in Y andadapted to have the branches of the Y directly connected to athree-phase power source, a switch in series with said condenser,armatures within said coils, and a movable pointer member, saidarmatures being opposingly connected to said pointer to effect movementthereof by unbalance between the pull on said armatures.

2. An electrical phase sequence indicating instrument comprising a pairof coils and a condenser continuously electrically connected in Y andadapted to have the branches of the Y directly connected to athree-phase power source, a switch in series with said condenser,armatures within said coils, and a pivoted pointer member, saidarmatures being connected to equal lever arms of said pointer.

S. An electrical phase sequence indicating instrument comprising a pairof coils and a condenser continuously electrically connected in Y andadapted to have the branches of the Y directly connected to athree-phase power source, a switch in series with said condenser, apivotally mounted indicator, armatures associated with said coils andconnected to said indicator with equal and opposite lever arms withregard to said pivot, and spring means arranged to bias said indicatorto a neutral position.

4. An electrical phase sequence indicating instrument comprising a pairof coils and a condenser connected in Y and adapted to have the branchesof the Y directly connected to a threephase power source, a switch inseries with said condenser, an indicator, a pivot for said indicator,armatures associated with said coils and connected to said indicatorwith equal lever arms with regard to said pivot, and tension springmeans connected between said indicator and a fixed portion of saidinstrument and radially disposed with respect to said pivot.

5. An electrical phase sequence indicating instrument comprising a box,a cover, an upper support member secured to said cover, a condenser anda switch secured to said upper support member and electrically connectedin series, a lower support member having a U-shaped lower end, a pinconnecting said U-shaped end to said cover and extending between thearms of said U-shaped end, an indicator having a U-shaped end with itsarms pivotally mounted on said pin, a pair of coils secured to saidlower support and electrically connected in Y with said condenser,armatures associated with said coils and con- 5 nected to said indicatoron opposite sides of said pin and a tension spring connected between onearm of the U-shaped end of said indicator and said upper support andextending radially from said pin.

6. An electrical phase sequence indicating in` strument comprising apair of coils and a noninductive impedance connected in Y and adapted tohave the branches of the Y directly connected yto a three-phase powersource, a switch connected in series to said impedance, said coilshaving a continuous electrical connection, armatures Within said coils,a pointer member, said armatures being connected to equal lever arms onsaid pointer, and test leads adapted to be connected to a circuit to betested and connected to the free ends of said coils and impedance andseries switch.

7. An electrical phase sequence indicating instrument comprising a pairof coils and a noninductive impedance connected in Y and adapted 6 tohave the branches of the Y directly connected to a three-phase powersource, said coils having a continuous electrical connection, armatureswithin said coils and a pointer member, said armatures being connectedto lever arms on said pointer.

LEON L. SIMKINS.

REFERENCES CTED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

